<PAGE>   1

                                                                     EXHIBIT 4.8

                                                                               1



                              GUARANTEE SUPPLEMENT

                  GUARANTEE SUPPLEMENT, dated June 5, 1998, to the Guarantee,
dated as of June 7, 1989 (the "SUBSIDIARY GUARANTEE"), made by the corporations
that are signatories thereto in favor of THE CHASE MANHATTAN BANK (as successor
to Chemical Bank (as successor to Manufacturers Hanover Trust Company)), as
agent (in such capacity, the "AGENT") for the banks (the "BANKS") that are
parties to the Credit Agreement referred to below.

                              W I T N E S S E T H :
                              - - - - - - - - - - -

                  WHEREAS, American Media Operations, Inc. (as successor to
Enquirer/Star, Inc. (as successor to GP Group, Inc.)), a Delaware corporation
(the "COMPANY"), the Banks and the Agent are parties to a Credit Agreement dated
as of June 7, 1989, (the "ORIGINAL CREDIT AGREEMENT") as amended by the Amended
and Restated Credit Agreement, dated as of June 28, 1990, the Second Amended and
Restated Credit Agreement, dated as of May 12, 1992, the Third Amended and
Restated Credit Agreement, dated as of November 10, 1994, and the Fourth Amended
and Restated Credit Agreement, dated as of June 5, 1998 (as amended,
supplemented or otherwise modified, the "CREDIT AGREEMENT"), among the Company,
certain of its subsidiaries, certain banks and other financial institutions, and
the Agent, and, in connection therewith, certain subsidiaries of the Company
have executed and delivered the Subsidiary Guarantee in favor of the Agent; and

                  WHEREAS, pursuant to the provisions of subsection 7.3 of the
Original Credit Agreement the Company has agreed that, in the circumstances
described therein, it would cause certain Persons which, after the date of the
Original Credit Agreement, become subsidiaries of the Company to become parties
to the Subsidiary Guarantee by executing and delivering supplements thereto in
the form of this Guarantee Supplement; and

                  WHEREAS, the undersigned (the "NEW GUARANTOR"), which was not
originally a party to the Subsidiary Guarantee, has become a Subsidiary of the
Company and wishes to become a party to the Subsidiary Guarantee;

                  NOW THEREFORE, the New Guarantor and the Company hereby agree
as follows:

                  1. The New Guarantor agrees to be bound by the provisions of
the Subsidiary Guarantee and agrees that it shall on the date of this Supplement
become a Guarantor for all purposes of the Subsidiary Guarantee to the same
extent as if originally a Guarantor thereunder.

                  2. To induce the Agent to accept this Guarantee Supplement and
to continue to extend credit to the Company pursuant to the Credit Agreement,
the Company hereby confirms that all the representations and warranties set
forth in Section 3 of the Credit Agreement, insofar as they relate to "Credit
Parties" and "Credit Documents", shall include


<PAGE>   2
                                                                               2








the New Guarantor and the Subsidiary Guarantee, as supplemented by this
Guarantee Supplement, respectively, and hereby represents and warrants that such
representations and warranties are correct in all material respects on the date
hereof.

                  3. Term defined in the Credit Agreement shall have their
defined meanings when used herein.

                  IN WITNESS WHEREOF, the undersigned has caused this Guarantee
Supplement to be executed and delivered by a duly authorized officer on the date
first above written.

AMERICAN MEDIA OPERATIONS, INC.

By:
   ---------------------------
   Title:


FRONTLINE MARKETING, INC.


By:
   ---------------------------
   Title:


Accepted this 5th day of 
June, 1998.


THE CHASE MANHATTAN BANK,
as Agent

By:
   ---------------------------
   Title:


<PAGE>   3





                                                                               3




                              GUARANTEE SUPPLEMENT

                  GUARANTEE SUPPLEMENT, dated June 5, 1998, to the Guarantee,
dated as of June 7, 1989 (the "SUBSIDIARY GUARANTEE"), made by the corporations
that are signatories thereto in favor of THE CHASE MANHATTAN BANK (as successor
to Chemical Bank (as successor to Manufacturers Hanover Trust Company)), as
agent (in such capacity, the "AGENT") for the banks (the "BANKS") that are
parties to the Credit Agreement referred to below.

                              W I T N E S S E T H :
                              - - - - - - - - - - -

                  WHEREAS, American Media Operations, Inc. (as successor to
Enquirer/Star, Inc. (as successor to GP Group, Inc.)), a Delaware corporation
(the "COMPANY"), the Banks and the Agent are parties to a Credit Agreement dated
as of June 7, 1989, (the "ORIGINAL CREDIT AGREEMENT") as amended by the Amended
and Restated Credit Agreement, dated as of June 28, 1990, the Second Amended and
Restated Credit Agreement, dated as of May 12, 1992, the Third Amended and
Restated Credit Agreement, dated as of November 10, 1994, and the Fourth Amended
and Restated Credit Agreement, dated as of June 5, 1998 (as amended,
supplemented or otherwise modified, the "CREDIT AGREEMENT"), among the Company,
certain of its subsidiaries, certain banks and other financial institutions, and
the Agent, and, in connection therewith, certain subsidiaries of the Company
have executed and delivered the Subsidiary Guarantee in favor of the Agent; and

                  WHEREAS, pursuant to the provisions of subsection 7.3 of the
Original Credit Agreement the Company has agreed that, in the circumstances
described therein, it would cause certain Persons which, after the date of the
Original Credit Agreement, become subsidiaries of the Company to become parties
to the Subsidiary Guarantee by executing and delivering supplements thereto in
the form of this Guarantee Supplement; and

                  WHEREAS, the undersigned (the "NEW GUARANTOR"), which was not
originally a party to the Subsidiary Guarantee, has become a Subsidiary of the
Company and wishes to become a party to the Subsidiary Guarantee;

                  NOW THEREFORE, the New Guarantor and the Company hereby agree
as follows:

                  1. The New Guarantor agrees to be bound by the provisions of
the Subsidiary Guarantee and agrees that it shall on the date of this Supplement
become a Guarantor for all purposes of the Subsidiary Guarantee to the same
extent as if originally a Guarantor thereunder.

                  2. To induce the Agent to accept this Guarantee Supplement and
to continue to extend credit to the Company pursuant to the Credit Agreement,
the Company hereby confirms that all the representations and warranties set
forth in Section 3 of the Credit


<PAGE>   4

                                                                               4





Agreement, insofar as they relate to "Credit Parties" and "Credit Documents",
shall include the New Guarantor and the Subsidiary Guarantee, as supplemented by
this Guarantee Supplement, respectively, and hereby represents and warrants that
such representations and warranties are correct in all material respects on the
date hereof.

                  3. Term defined in the Credit Agreement shall have their
defined meanings when used herein.

                  IN WITNESS WHEREOF, the undersigned has caused this Guarantee
Supplement to be executed and delivered by a duly authorized officer on the date
first above written.


AMERICAN MEDIA OPERATIONS, INC.


By:
   ---------------------------
   Title:


RETAIL MARKETING NETWORK, INC.


By:
   ---------------------------
   Title:


Accepted this 5th day of 
June, 1998.



THE CHASE MANHATTAN BANK,
as Agent

By:
   ---------------------------
   Title:


<PAGE>   5
                                                                               5




                              GUARANTEE SUPPLEMENT

                  GUARANTEE SUPPLEMENT, dated June 5, 1998, to the Guarantee,
dated as of June 7, 1989 (the "SUBSIDIARY GUARANTEE"), made by the corporations
that are signatories thereto in favor of THE CHASE MANHATTAN BANK (as successor
to Chemical Bank (as successor to Manufacturers Hanover Trust Company)), as
agent (in such capacity, the "AGENT") for the banks (the "BANKS") that are
parties to the Credit Agreement referred to below.

                              W I T N E S S E T H :
                              - - - - - - - - - - -
      

                  WHEREAS, American Media Operations, Inc. (as successor to
Enquirer/Star, Inc. (as successor to GP Group, Inc.)), a Delaware corporation
(the "COMPANY"), the Banks and the Agent are parties to a Credit Agreement dated
as of June 7, 1989, (the "ORIGINAL CREDIT AGREEMENT") as amended by the Amended
and Restated Credit Agreement, dated as of June 28, 1990, the Second Amended and
Restated Credit Agreement, dated as of May 12, 1992, the Third Amended and
Restated Credit Agreement, dated as of November 10, 1994, and the Fourth Amended
and Restated Credit Agreement, dated as of June 5, 1998 (as amended,
supplemented or otherwise modified, the "CREDIT AGREEMENT"), among the Company,
certain of its subsidiaries, certain banks and other financial institutions, and
the Agent, and, in connection therewith, certain subsidiaries of the Company
have executed and delivered the Subsidiary Guarantee in favor of the Agent; and

                  WHEREAS, pursuant to the provisions of subsection 7.3 of the
Original Credit Agreement the Company has agreed that, in the circumstances
described therein, it would cause certain Persons which, after the date of the
Original Credit Agreement, become subsidiaries of the Company to become parties
to the Subsidiary Guarantee by executing and delivering supplements thereto in
the form of this Guarantee Supplement; and

                  WHEREAS, the undersigned (the "NEW GUARANTOR"), which was not
originally a party to the Subsidiary Guarantee, has become a Subsidiary of the
Company and wishes to become a party to the Subsidiary Guarantee;

                  NOW THEREFORE, the New Guarantor and the Company hereby agree
as follows:

                  1. The New Guarantor agrees to be bound by the provisions of
the Subsidiary Guarantee and agrees that it shall on the date of this Supplement
become a Guarantor for all purposes of the Subsidiary Guarantee to the same
extent as if originally a Guarantor thereunder.

                  2. To induce the Agent to accept this Guarantee Supplement and
to continue to extend credit to the Company pursuant to the Credit Agreement,
the Company hereby confirms that all the representations and warranties set
forth in Section 3 of the Credit


<PAGE>   6
                                                                               6



Agreement, insofar as they relate to "Credit Parties" and "Credit Documents",
shall include the New Guarantor and the Subsidiary Guarantee, as supplemented by
this Guarantee Supplement, respectively, and hereby represents and warrants that
such representations and warranties are correct in all material respects on the
date hereof.

                  3. Term defined in the Credit Agreement shall have their
defined meanings when used herein.

                  IN WITNESS WHEREOF, the undersigned has caused this Guarantee
Supplement to be executed and delivered by a duly authorized officer on the date
first above written.

AMERICAN MEDIA OPERATIONS, INC.

By:
   ---------------------------

   Title:

AMERICAN MEDIA MARKETING, INC.

By:
   ---------------------------
   Title:

Accepted this 5th day of June, 1998.

THE CHASE MANHATTAN BANK,

as Agent

By:
   ---------------------------
   Title: